Mike Pence has been trying to plead ignorant about Donald Trump's many missteps. The trouble is that other evidence incriminates him every step of the way.
When Pence says he didn't know something, it may mean that he ignored or failed to attend the warnings or information.
At any rate, Trump and his entire campaign are in a bucket of collusion, and Robert Mueller is taking inventory of what is in the bucket. He readily gets the picture while agents continue to find the missing pieces.
They share everything.